Spark-plug.



SPARK PLUG. APPLICATION FILED JM. z5, 1907.

Patented 2m1y.8,1913

WWII n 6135's es:

UNTED SPAIE.Sn PATENT OFFCE.

FREDERICK T. H. BACON, OF NEW 'YORK, N. Y.

SPARK-PLUG.

liv it l nown Athat l. 'Fiumi-:nulli l`. .ll. llxvox, a suhjvrt ot thv King ol`.llngland, andvrvsidvnt olI h'vw York, in thv count)1 oli Now Yoili and h'tatvy o'tf Now York. havn iu \'vntrtl vvrtain uvw and `usvt'ul llluproyvnlvuts in Sp:\rlt-llilgs, ot whit-h thv` It'ollowingr is a spvuilivatiou.

'lhis invvution rvlatvs to spark plugs `for ignitiug ronlluistihlv rasvous rhargvs' in iutvrnal vonihustion vng'invs; and thv niain ohivrt ol' thv in\vutiou is to providv au'iniprovvd dvvivv otI this ltind which van hv, rvadily assvnihlvd and disassvlnhlvd and in whivh thv vrvvpinlg' distanvv to hv travvrsvd liy :uuunullatious ol' "arlion or othvr partially uoudurtirv niatvrial is so grvat that thv dvvivv van not liv short virtfuilvi'l.

()tlivr l'vatlu'vs ol' lny in\'vntiou not hvrv inhvt'orv rvl'vrrvd to will hv hvrvinal'tvr dvsvrilivd and arv illustratvd in thv arvolupanylug dra wings, in whivh Figaro l is au vnd Vivw of a sparltplugl vnihodidnal iny iuvvntion showingI thv parts about t-wirv thv natural sizv, Fig'. 2 is a vvutral longitudinal svrtiou o'l' thv santv. Figs. Il, laud 5 arv rvntral longitudinal svrtions oll insulating nivinhvrs ol thv sparlvplug whivh will ho livrviuatitvr dvstfrihvd in dvtail.

Similar,t'liarartrrs dvsignatv liltv parts in all'thv igurvs nl' thv drawing.

l`l1v niain vlvnivnt olA luy spara-plug will prvl'vrahly hv a uonduvlig plu sY adaptvd to` hv svvnrvd in plat-v i'.. a wall ot an inlornal voniluisliou vnsffnv. 'I`liv vonstruvtiou olthis vlvinvnt` nrd not dvpart troni vstahlishvd pravtif'w. and in thv drawings a vonrvntioual tyIra-'ol' plug is dvsignalvd hy 2. il having at'1 thv inuvr vnd tliorvol' vxlvrnal srrvwtlu'vadsI il hy wliivh it is svvurvd in plarv iu thv wvllknown luannvr in a vorrvsponding iutvrnall'y/thrvadvd opvnn."r in thv wall of the vnginv, and having at thv outvr vnd a nllt- Ll hy nivaus ot' wliivlr thv spark-plug may he turnvd. 'lliis ronduvliirL` plug 2 has svourvd thvrvto' substantially iu thv usual niauuvr. ouv vlvvtrodv V, whit'li is thv outvl vlvrlrodv ol' thv spark-plug. Tho othvr or vvutral vlvvlrodv ol thv spark-plug' may hv, as illustratvd` sulistantially ot tho usual (construction. ilV hvinpj hvrv shown as a` rod or wirv t3 ol' unilorni vross svrtion with itsl Ifrvv` vnd disposvd in, thv propvr relation to thv lrvv vnd oll thv outvr vlvvtrodv 5, that` svparatvd thvrvt'roni hy a sniall air-gap across whirh thv vlvvtfriv t'lisvhargv will taltc Specification of Letters Patent.

atvutod July 8,1 913.

Application filed January 25,'1907. 'Serial No.1354,00`6.

pl'af'o and forni fa Spark. The vvntral vlootrodv (l inayfhv ouuvtzlvd with its invtallif: support or tvrininal in any suitahlomannerj it livingy in thv vonstriutiou illustratvd drivvn into au axial apvrturv in thvhvad olf a 1011;;l svrvw T haring;l a loup; smooth shank' and a short thrvadvd vnd Tho hoad'of thv svrvw is dvsignatvd hy't).

'lhv vondurting plug 2 and the svrvw 7 thus ronstitutv in tho construction illustratvd thv vondlu'ting` supports for thv, ro spvrtirv vlvvtrodvs antl't'. rIhvso two vondarling supports must. as'iu tho -aso ol 'all othvr spark-plugs. hv separated l y vlvvtriall insulating' xnatvi'ial having high rvsista'nt'v, and I prvl'vr to vinploy Vt'or this p'urposv niatvrial ol thv lava t \pv. which not oillyhas high rvsistanvv hut is dvnsv aud is'pravtirally unatl'vvtvd hy any ('lvgrvo olitvnipvraturv to whivh it may hv vxposvd in an intvrnal vonihustion vngjiuv. rlhis insulating inatvrial must not only ,svparatv thv vonduvtin; supports carryingl thvy vlvvtrot'lvs 5 aud'tl1 hut in this vasv` will ho so `lorinvd asto lio in rloso vontart` with thv innvr wall ol' tho ronduvtingj plufi', surround thv vvutra'l vlvvtrodv t3. and Vtorni around said rvntral vlvrtrodv and hctwvvn it` and lh" 521x111 all ot thv condor-tiny, plug at lvast ouv dvvp spat-v :-,urioil|uling suvh vlvvtrodv. ln thv voustruvtion illustratvd a siuglv dvvp sparo is l'oruivd in thv insulating` Inatvrial. and this sparo surrounds and is tfonvvntriv with thv vvntral vlvrtrodv t. Said sparo is dvsip'- natvd hy lt). Alloth walls ot this sparv aro insulatingl walls, ouv wall living.;y indicated aL ll and thv othv' at 'lho two insulating walls thus l'ornivd aro svparatvd by a sparo l() ol` vonsidvralilv width and aro usually, as shown. sulistanl ially parallvl with vavh othvr and with tho axis of thv central vlvvtrodv t3. 'lhv` sparo l() t'orinvd in tho insulating inalcrial is here illustratvtl as aunular and voluplvtvlv si|1'1o1uuls"tlxv central vlvctrodv, and at all points about its axis-thv elvtftrotlv t3 svparatvd t'roui'thc insulatingf plug 2 hy at lvasly two insulating walls spavvtl a Considvrahlv. distanvt: apart. The depth ot the spavv lt) surrounding thocvntral electrodo and toruivd try two insulating walls, one surrounding thv othvr,111ay var)r consider-- alily` but in all vasos it; should bv a tlcvp space, and a Considvraltle distanvv should svparatv thv twv walls thvrvof, iu ordvr'tllat dvpositvd Carbon and other partially vontluctirc material niuyll thv-space gradually from the closed to the open end thereof and not bridge the open end of the space until the closed end is tilled with such material. ll'hen the space is ot the depth illustrated, which is approximately equa] to the internal diameter of the'conducting plug` 2, it will be seen that t-he insulating material separating the cent-ral electrode from the conducting plug 2 has a plurality of insulating walls which form a. creeliing surface of great length, the aggregate length ,being approximately thc same as or less than the internal' diameter of the conducting plug.

The insulating material used is here illustrated as divided as a matter of convenience and economy into several parts, though whether the insulating material considered as a whole be t'ormed in onel piece or in several pieces. is unimportant.. That portion of the whole bodyot insulating material which is adjacent, to the inner end of the sparkplug and inclosed within the externallythreaded portion of the conducting plugl may to advantage be made in two parts, each having anA opening lengthwise thereof, and constituting a hollow body, preferably cylindrical. One such insulating cylinder is indicated at 13. the opening therethrough being of large diameter to receive the other. The second ot' these cylinders has a bore of small diameter extending therethrough, and its outer surface or'wall, when the parts are assembled, is surrounded by the vinner wall ot the cylinder 113 but separated therefrom by a deep and' relatively wide space. The opening through this cylinder 14 is indicated at 15. lt preferably is of suoli diameter as to lie in close contact with the sur-A li'ace ol the central electrode 6, which passes through it. In a similar manner the outer wall ol' the cylinder t8 is shown as covering the inner wall ot the coinflucting plug 2, thus matting close contact with such inner wall. .lt will hc seen that the inner wall ot the cylinder lil and the outer wall ot the cylindmf l-t; constitute the separated insulating walls il and 'l2 hert-,inbetore re licrrcd to. The relative positions ot the two cylindersl when assembled are clearly illustrated in Fig. 2. construction, slightly lrter than the main The insulating cylinder 13 is in this" portion, that is the inner end, of the conducting plug 2, and may abut against and be stopped by an internal annular flange 1G at the extreme inner end o'i the conducting plug. This llange also provides an additional body oi metal through which the outer electrode 5 may be driven and by. which said electrode may be held firmly. r["he cylinder lt may also have an annular lflange 17 oi the same material by means of which it will be located in position lengthwise of t-he spark-plug. Here this flan-ge abuts against an annular shoulder 2 in the conducting plug 2.

The cylinder 14 with its annular fiange 17 constitutes in the construction illustrated one member of the insulating core of my improved spark-plug.A As illustrated said insulating core is made in two pieces, the other member being a cylinder 1S of larger diameter than the cylinder 14 and formed at its inner end with an annular flange 19. This insulating member has a central longitudinal bore of two diameters7 o-ne portion 2O being short but of large diameter to receive the head 9 of the screw 'T and form a stopshoulder 21 for said head, while the other portion of thebo're is long and of smaller diameter, as shown at 22, to receive the smooth shank of the screw 7. By dividing g the insulating core into two parts the parts may be made more cheaply andthe sparkplug more readily"assembled. The two members of the insulating core will-usually be united-by a body of cement 23 after the/100 electrode 6 and the screw 7 have been placed in thc respective parts of said insulating core and the electrode 6 has been driven into the head oi said screw.

The insulating core with its assembled central electrode and screw `may lbc held in place in the conducting plug 2 iii any suitable manner. A vhollow screw-cap 24 of well-known type may be employed for the purpose. threads which fit into corresponding internal threads in the outer end of the conducting plug 2. lVllen this cap is screwed home, the enlarged flanged portions ot the members 14 and 18 of the insulating core are held 115 firmly between the inner endof said screwcap and the shoulder 2.

The outer end of the spark-plug may be finished substantially in the usual manner by means ot a conducting cap such as 25 and 120 a nut 2G cn the threaded end 8 o,'i the screw 7.

liu use, :1` spark-plug eoustructergl in accordance with my invention. having a. centra] clertrodi,I fm`ipcratiug with au outer electrode fastened in. a omaha-thug' plug and 125 also having between the central electrode and the t-.oinluc'ting plug insulating material embodying deep insulating walls surroundingl the central electrt'ale and spaced a. cousiderable distance apart to increase the 130 This cap has external screw- 

